What can result from prechlorination of raw water?

Prechlorination of raw water is a process that involves adding chlorine to the water before it undergoes further treatment steps. This practice primarily serves to disinfect the water, but it also has implications for the formation of disinfection byproducts, particularly trihalomethanes (THMs). Trihalomethanes are a group of chemical compounds that are formed when chlorine reacts with organic matter present in the raw water.

When chlorine is applied during prechlorination, it can react with natural organic materials to produce THMs as byproducts. This is a significant consideration in water treatment because excessive levels of THMs in drinking water can pose health risks. Therefore, the formation of trihalomethanes is a crucial outcome to monitor when chlorination is performed, especially before further treatment processes.

While prechlorination can influence other factors such as chlorine demand and bacterial growth, the notable result that aligns specifically with the chemistry of chlorine reactions with organic matter is the formation of trihalomethanes. Understanding this relationship is vital for water treatment plant operators to effectively manage and mitigate the production of disinfection byproducts while ensuring the safety and quality of drinking water.